buffington



Patented Nov. 1, 1927.

Laurea UNITED STATES PATENT OFFICE;

HARRY C. BUEFINGTON, OF'SPRINGFIELD, ILLINOIS, ASSIGNOR T0 WEAVER MANTI-IFACTURING COMPANY, OF SPRINGFIELD, ILLINOIS, A CORPORATION OF ILLINOIS.

TRUCK JACK.

y Application filed September With the advent of balloon tire equipmenton automobiles andbetter highway or road conditions, it has beenpossible and has be# come more or lesscommon practice to constructautomobiles with lower centers` of gravity and with relatively lowaxles, which become still lower when one or both of such tires havinglarge cross-sections are deflated.

Vlith the ordinary type or style of truckjaclr, the load-lifting saddlegenerally carried within the wheelebase of the jack would require wheelsof such small diameter to go under the axle that it would be difficultto move 'the jack with its load on the floor of the average garage andthe lifting mechanism would havegto be so low to the floor that it wouldbe arduous to obtain a design which would permit the lifting saddle todcscendsufliciently to reach under the aXle in its extremely low pointand then lift high enough so that the tires of the automobile wouldclear the floor suiiiciently to permit them to be removed for repair orchange.

rihe design of the new jack incorporating the present invention is suchthat all of the objectionable features of the conventional type oftruck-jack have been eliminated, the new appliance having the low Saddleand the high wheels for easy moving of the load and also havinganextremely high lift enabling the tires ofthe automobile to be removed`other and with a `lifting-Saddle having a lower reach or descent thanthe height of the carrying-wheels. In the new appliance, in someembodiments at least,`the liftingsaddle extends ahead of thecarrying-wheels y and is capable of lifting or raising the load upwardlyandbacltwardly of such wheels so that the load finally reaches a pointwithin the wheel -base of the jack.

rlothe accomplishment of these and other aims and objects lhave devisedthe present reference numerals have been Vemployed to ferredembodimentof the invention il# 21, 1925. serial N6. 57,505.

designate the same parts, but it is to be borne in mind that theinvention is sus ceptible of a` variety of embodiments differing more orless in mechanical details but all incorporating the fundamentalprinciples involved which have been deiined in the appended claims.

In these drawings:

Figure 1 is a side elevation of the new truck-jack with the load-liftingsaddle in lowered position;

Figure 2 is a plan view of the structure depicted in Figure l with aportion of the operating handle omitted;

Figure 3 is an enlarged, fragmentary, longitudinal section through theappliance with the loadlifting saddle in its lower-most posi tion;

Figure 4l is a fragmentary, horizontal seotion on line 4 4 of Figure 3Figure 5 is a vertical section on line 5-5 of Figure 3;

Figure 6 is a vertical cross-section on line 6-6 of Figure 3;

Figure 7 is a partial lengthwise section through the upper portion ofthe actuating handle;

Figure 8 is a longitudinal sectional view of a portion only of theappliance showing the loadengagingsaddle partially elevated andindicating the foot of the frame as ene gaging the door; and

Figure 9 is a fragmentary, lengthwise section illustrating theload-engaging saddle in fully raised position.

Referring to the plurality of views of these drawings for anunderstanding of the details of the structure, it will be perceived thatthe appliance includes a longitudinallydispo'ed, tubular element 21desirably square in cross-section.

On one end of this intermediate member 21, a` hollow casting 22 ofappropriate shape top and bottom edges, such arms having upstandingflanges 32, 32, Y

By means of a peculiar mechanism liereinafter described, this foot, whenthe loadengaging seat or saddle is in lowered posi-` tion as shown inFigure l, is raised or lifted slightly from the floor so that the truclrmay be rolled thereon with facility, but during the elevation of theload, the foot rests on the iioor as presented in Figure 8, and when theload has been fully lifted, the foot rises again from the floorV so thatthe' truck may be wheeled around, as illustrated in Figure 9.

The tubular truclcfranie element 2l accommodates inside of it alongitudinal, reciprocatory ratchet-bar 33 provided on .its top surfacefor a portion of its length with ratchet-teeth 34, as indicated inFigures 3 and Ll, such bar 33 being of a length to ez;- tend rearwardlyfrom the frame construction when the seat or saddle is in its lower-Vmost position, whereby, as willY be understood from what follows, theoperator by pressing on the end ofthe bar with his foot Y' may lift thesaddle readily until it comes for the accommodation of a transverse axle39 which at its two ends, by means of roller Vbearings lll, is equippedwith comparativelylarge front carrying or supportingswheels 4t2, 42freely rotatable on the axle, each wheel on its inner face havingahollow drum i3 adapted enteriorly to coa'ct with the cam surface 3l ofthe corresponding part 23 Vof thek main-frame element 27.

As is clearly indicated in Figure 6, the inner edges of these drums 43,43 c-oact with the fianges'32, 32 to hold the axle and wheels in normalcentral position.

As is also shown in this Figure 6, such shaft or aXle 39, just inwardlyof thehubs of the two front carrying-wheels 42, 42, is supplied with-fapair of vertical plates 441,441 provi-ded centrally with apertures ofsubstantiallythe sam-e -dia-meter as and receiving the axle V39, eachjof,these plates along its vertical `margins having" inwardly-disposedguidedlange's 45, l5 overlapping corresponding, upright, `guide-surfacesof the complementary arms 37 of the yoke 36, each of Such plates :44 onits `lower portion being Larnaca supplied with a transverse stop lug 46adapted, under certain circumstances, by engagement with the top edge ofthe companion flange 32 to limit the upward movement of that part of theframe.

Between the yolre arms 3T, 37, the axle 39 has a wheel t7 freelyrotatable thereon by reason of an interposed roller-bearing 43, thiswheel being designed and adapted to actuate or operate the load-liftingand lower ing lever i9 of inverted U-shape in crosssection andfulcruinedon the main-frame or casting 27 and fixed on a cross-pin orrod .5l oscillatory in bearings `in the main-frame, the upward turningor rocking movement of such arm or lever 49 being limited or restrictedby a short extension 52 thereon adapted to engage a stop or abutment 53on the casting 27 as illustrated, for instance, in Figure 9.

This load-actuating arm or lever near its free end has a seat or saddle5st adapted to receive the load, such as the axle of an automobile.

Vit 55, the .lever ti9 has an extension 56 fulcruii'ied or hingedthereon, this extension being likewise of U-shape in cross-sectioii andlorniing when in action a direct prolongation of the lever 49, theextension and lever being connected together by a coiled contractilespring 57 which tends to fold the extension into inoperative position,as shown, for instance in Figures 3 and 3.

ln order to limit the turning action or movement of the extension on itspivotal mounting, so that it may constitute afdircct and properprolongation of the main lever 49, these two parts are provided withcooperating abut-ments 53 and 59, all as is clearly presented in Figure9.

it the other or rear end of the appliance, a tubular handle 61 having across-rod (i2 at its upper end is provided at ,its lower end with a.yoke-casting G3, the two spaced arms Gil of which are equipped withfulcrum screws 65 oscillatory in bearings 6G, (5G of the casting 22 (seeFigure t).

rihis operating-handle 6l has a chain (3T fastened thereto at 6e, theother end of the chain being connected to a coiled, contractile spring69, inside of the hollow member 2l, and fastened at its other end bymeans of a link or rod to an arm 50 rigid with the shaft 5l, as clearlyshown in Figure 3, the chain extending up out through the open top ofthe element 22, whereby the spring by its contractile action tends tocarry or rock the handle upwardly until it engages a stop il limitingsuch movement..

The lower end of the handle-castingl 63 is in the form `of a short,double bell-crank arm between the .spaced parts of which at 72 anactuating-pawl 73 is` fulciumed, its tooth being adapted to cooperatewith those of the ratchet-bar 33 in the lifting and lowering operationof the load-engaging1`ever,lsaid pawl being pulled down to its work by acoiled,contractile"jspring 74: connected at one end to the `casting 22and at` its other end to a projection on thepawl, the latter having atransverse, projecting pin `75.

Pivoted at7G, 7G in the two sidewalls of the casting 22 is a U-shapedpawl member 77 equipped with a tooth or dog `78 and also supplied with atransverse or cross-pin 79, this element 78 constitutingthe locking orholding pawl coacting `with the teeth or shoulders of the longitudinalratchet-bar.

Pivoted oncue of the operating-handles trunnion` screws G5, I employ auoffset pawl' controller 81 underlying the two `pins 75 and 79 andadapted to be raised or elevated during` the lowerii'ig operation of thejacllby means of achain 82 connected at one-end to an outstanding' armS3 thereon, the other end of the chain, which extends through an openingin the wall of handle 61, being joined by a springl 8a and associatedlink 85 to a small handle 86 fulcrumed at 87 between outstandingbracket-arms on the upper portion of the main-handle 61, such leverhandle 86 being located and n'iovable in slots S8 in opposite walls ofthe upright handle, whereby, when the hand grasps the cross-bar 62 andholds the lever or handle 86 toward it, the pawl-controlling member' 81will be lifted, the top edge of the latter being of the cam" formationshown in Figure 3 to correctly perforlnthe functions hereinafterspecified.

The somewhat unusual mode of operation of vthis appliance occurspractically as follows. l

vWhen the load-engagingl seat or saddle 511; is in its lowermostposition as shown `in Figure 1, itis in front of the pair ofcarrying-wheels i-2 of substantial diameter and considerably below theirtops, whereby canbe readilyintroduced below a compara, tively low axle,such asis usually present in an automobile when a pneumatic tire of theballoon type has lost its air-cushion as by puncture or otherwise.

rlhis'saddle or seat may beeasily pushed under such. axle by merelyrolling the truck intoproper .'positioii, because theeirtensioni foot29`is then raised slightly off of the floor, as illustrated in Figure 1,by reason of the pulling action of spring 69` which rocks the frame,ofwhich the extension foot forms a part, around the point of contact` ofthe lifting wheel or rollerl with the lever 49, the `carrying-wheelsunder these circum- 1 stances,` bearing on the floor and permitting suchfoot-elevating action because their drums, 4&3, then register withdepressions 131 in the. `"cani surfaces 31.

Assuming that the truck-jack has been. correctly located inposition sothat the seat` or saddle is 'below the part of the vehicle to be engagedby it, the ope at-or first quick ly elevates `the saddle by pressing`forwardly with his foot on `the protruding rear end of the ratchet-barand then by grasping the cross-bar or transverse-handle` (l2, he rocksthe operating-handle G1 up and down in a vertical plane more or less inopposition to the lifting tendency of the spring` 69; f Such pumpingaction of the handle forces the ratchet-bar 63 lengthwise forwardly awayfrom the handle step bystep in a 1nanner well understood in this art;that is to say, when the handle descends it causes the pawl `Z3 to feedthe bar along one notch or tooth, or more if (fl-esired, in which newposition the bar is 'stained by the holding or locking pawl 78 while theother pawl is receding during` the upward swing of the handle to engagea new tooth.`

A repetition of this rocking action of the handle moves the bar alongintermittently.

As the pand-'actuated ratchet-bar 38 shifts lengthwise step by step inthis manner, the drums or rollers a8, i3 travel up out of th shallow camrecesses 131, 131 on to the parts 182, 132 of the cams, and, as soon. as,this taires place, the wheels no longersupport that end ofthe truclrbut they force the foot 29, which forms a part of the rigid frame, todescend slightly and engage the floor beneath the saddle, as shown inFigure 8.

llVere it not for this foot acting in' the manner stated, 4as soon asthe saddle assumed the load forwardly of the wheelbase of the truck, itwould tilt the latter upwardly in a way to depii'ive'the appliance ofthe accomplishn'ient of satisfactory results, but.` inasmuch as the footsupports the load from directly beneath, no such `occurrence takesplace.

The downward pressure of such extension foot on the. floor alsoeliminates any possibility of the `truck rolling` out of the desired.and correct position.

` As these carrying-wheels thus roll along on the cam tracks, theytravel. forwardly or outwardly under the load which previoiisly was`beyond them, and when the drums 43 reach the'pcrtions 133, 133 of thecams.` the wheels again assumetheir carrying funcv tion, because thefoot is then automatically raised off of the floor, as illustrated inFigure 9,'and the truck and its load may be whecledaround, as desired. ll

During this outwardor forward travel of the carrying-wheel 42, 42, thesmaller, rounded, intermediate lifting-wheel el? rolls along under thelever 4-9 gradually upwardly rockL ing it and its load carriedby thesaddle 54. Then thisconjoint outward movement of thethree wheels isfirst initiated, the exten sion 56 is folded `under lthe wheel el? byreason of the contraction ofitscontrolling spring 57,",but, as thewheels `travel along, this extension, by the engagement `of the 'allawheel Aor roller 47 `with it, is automatically straightened out againstthe pulling action of the spring 57, whereby it forms a direct extensionof the lever 59,;and the latter portion of the load-'lifting operation,performed by the bodily travel of the wheel 47, is brought about throughthis extension 57 and the cooperating stops or abutments 58 and 59, theextreme position or elevation of the seat or saddle 54 and thecorresponding positions of the .lever extension and the foot of theframebeing clearly indicated in Figure 9. Y

Thus it will be perceived 'that the greater part of the load-elevatingoperation is performed or carried out while the foot 29 is in contactwith the floor and hence there is no danger of the truck-jack rollingout-of place during that action, although the carrying-wheels are freeto turn and the foot is raised before the load is imposed Von the jack,thus permitting the latter to bereadily placed in correct position toassume the load, and after the load has been fully lifted, so that itmay be transported by the jack as may be required.

YThe reason that the foot rises from the Hoor when the load has beenfully raised is because of the shape of the cam surfaces 3l, 3l whichpermit the carryingwheels to bear on the fioor at that time due to theinclines 133, 133.

Under these conditions, as the wheel 47 performs .the last portion ofits lifting action by upwardly' rocking lever 49 through,

its extension 56, it lifts the whole frame, including the foot, by`reason of the engagement of the pair of abutments 52 and 53.

In order to prevent the cams 31, 31 from dragging or bearing on thedrums 43, 43 when the load yis raised to its full height, so that thetruck and its load may be rolled around with facility, the lugs 46, 46are employed on the plates 44, 44 and the top edges of flanges V32, v32,by contact with such elements 46, 46, limit or restrict the rise of thecams 31 3l sufficiently so that under the condition stated, they arethen out of contact with the companion drums. y Fromthe foregoing, Vitwill be'understood that the truck-jack Vhas relatively largecarrying-wheels whereby it ymay be easily rolled 4over a floor whencarrying its load, `that the latter 'is iirstengagedl by thejaclrforwardly ofi-its wheel-base and ultimately lifted andsimultaneously shifted inside of such base so that-it may be readilytransported, and that etlicient-means are provided to keep the jack fromtipping' up until theload has been brought within such wheel-base.

'To lower the load, the operator rocks the handle as before but at thesame timehe raises the small handle 36 sothat the carm-V controller 81is `in, action on the, ppawls, whereby the load descends :step by stepneaaaee a `manner common in jacks employing ratchets and enactingparvis.

The foot 29 is down on the floor during the greater part of such loaddescending action, but it is slightly above the floor before suchoperation begins and again after it is completed as will be readilyunderstood from what precedes.

During such load lowering function the extension 56 automatically foldsinto inoperative position as soon as it is permitted to do so.

The new invention is not restricted to this single embodiment, itsfundamental principles being broad in scope, as indicated by the annexedclaims, and hence capable of .incorporation in appliances dilferingradically in structure but all having its main structural and functionaladvantages.

I claim:

l. ln a truck-jack, the combination of a truck-frame, front and rearcarrying-wheel means therefor, a load lifting and lowering elementmovably mounted on said frame and which in its lower position projectsforwardly beyond and below the top of the front carrying-wheel means, anoperatinghandle, and means actuated by said handle to feed the frontcarrying-wheel means forwardly or rearwardly to operate said element,said means causing said front carrying-wheel `means to bear on the floorin the lowered and in an elevated position of the load `and to be`raised from the floor in intermediate positions of the load, the loadbeing assumed by said element forwardly beyond the wheel-base of thetruck and being within said wheel-base in its elevated position.

2. In a truck-jack, the combination of a truck-frame, carrying-wheelmeans therefor, said `frame having track-means on which thecarrying-wheel means is adapted to travel and having an `extension-footadapted to bear on the floor forwardly of said carryng-wheel means, anoperating-handle, a

load lifting fand lowering element on said frame, and coacting meanswhereby actuation of said handle effects the travel of saidcarrying-wheel means on said track-means, the elevation and lowering ofsaid element, the elevation Vand descent of said carryingwheel means,and the lifting and lowering of. sai d foot.

`3. In a truck-jack, the combination of a truck-frame, rearcarrying-wheel means therefor, front carrying-wheel means for ands'liiftable forwardly and rearwardly of said frame. a load lifting` andlowering' element extending forwardly beyond and adapted to assume theload `beyond the front carrying-wheel means, an extension `foot adaptedto `engage the floor forwardly beyond'said front carrying-wheel means,an 'operatinghandle, and coacting means whereby actualltl tion of saidhandle causes the lifting or lowering of the load, the extension orcontraction of the wheel-base of the truck, the raising and lowering ofthe front carryingwheel means from and to the floor, and the loweringand .raising of the extension-foot to and from the floor. i

4. In a truck-jack, the combination of` a truclnframe, rearca1'rying-wheel means therefor, front carrying-wheel means for andshiftable forwardly and rearwardly of said frame, a load lifting andlowering' element extending forwardly beyond and adapted to assume theload beyond the front carrying-wheel means, an extension `foot adaptedto engage the floor forwardly beyond said front carrying-wheel means, anoperating-handle, and coacting means where* by actuation of said handlecauses the lifting` or lowering of the load, the extension orcontraction of the wheelbase of the truck, the raising and loweringv ofthe front carrying-wheel means from and to the licor, and the loweringand raising of the extensionfoot to and from the floor, the frontcarrying-wheel means contacting,1 `with the floor both when theload isin lowered and in an elevated position,` the extension-foot en-`gfafringf the floor during; a portion of the load lifting and loweringoperation,`the load being` within said wheelebase when elevated andbeyond such wheel-base when in lowered position.

5. In a jaclethe combination of asupport, a load`-lifting articulatedautomatically-folding.;r lever extensible and contractible as to lengthfulcrumed on said support, a roller adapted to travel along said leverto effect the load liftingr and lowering rocking; action thereof, anoperating-handle, and connecting-means between said handle and rollerwhereby actuationof the former causes the travel of the latter. y

6. In a jack, the combination of a support, an articulatedautomatically-foldinn` load lifting and lowering' lever extensible andcontractible as to 'length fulcrumed on said support, a roller adaptedto travel beneath and in Contact with a plurality of the articulatedsectionsof saidlever to operate the same, a handle roekingly mounted onsaid support, and means whereby said handle may aotuate said roller stepby step including; a ratchet-bar, cooperating pawls and apawlcontroller. i

7. In a jack, the combination of a support. a load lifting' and loweringlever fulerumed on said support, a roller adapted to travel along and incontact with said lever to operate the latter, abandle rockinpglymounted on said support, and means whereby said handle may actuate saidroller step bystep including a ratchet-bar and cooperating pawls, saidratchet-bar beine; of suflicient length so that it may be pressed by theop erators foot to effect the initial movement thereof without resortingto the step by step action.

Ina truclnjaclr, the combination of a truclnframe, carrying-wheelstherefor eX- tensible and contractible as to wheel-base, a loadlifting;l and lowering lever fulcrumed on said frame, a roller adaptedto travel along said lever to roch the latter, an operating'- handle.y`an d means whereby actuation of said handle simultaneously effects thetravel of said roller and modifies the wheel-base of the truck.

9J In a truck-jack, the combination of a truck-frame, carrying-wheelstherefor extensibleand contractible as to wheel-base, an articulatedautomatically-foldingg load lifting' and lowering' lever fulcrumed onsaid frame, a roller adapted to travel alone' said lever to rock thelatter, an operatingdiandle, and means whereby actuation of said handlesimultaneously effects the travel of said roller and modifies `thewheelbase of the truck.

l0. In a trucleiack, the combination of a truclnframm a load 'liftingand lowering lever fulcruined on said frame, an axle mounted to shiftlengthwise said frame. a roller on said axle adapted to travellens-thwise the lever to operate the latter, carrying wheel means onsaid axle,y an operating;- handle, and connecting); means between saidhandle and axle whereby the former may bodily shift the latter to eifectthe travel of said roller and to change the wheel-base of the truck. Y

1l. In a truck-jack, the combination of a truck-frame, front and rearcarrying-wheel means therefor, a traclway along which said frontcarrying-wheel means may travel to modify the wheelbase of the truck,means on said frame to raise and lower the load, an operating-handletherefor, and means whereby actuation of said handle raises and `lowerssaid traclzway from and to the floor and causes the travel of the frontcarrying wheel means thereon.

l2. In a truck-jack, the combination of a truck-frame, front and rearcarrying-wheel means therefoiza load lifting and lowering' leverfulcrumed on said frame constructed to assume the load in advance of andlower than the top of said `front carrying-wheel means, and means toroel: said lever and its load upwardly by feeding?,v said frontcarryi1injwheel means forwardly relatively to `said frame to a pointwhere its airis is beyond the load, the lat-ter then being within thewheel-base of the truck.

18. In a truclnjack, the combination of a truck-frame, front and rearcarrying-wheel means therefor),` a load liftingf and lowering leverfulcrumed on said frame constructed to `assume the load in advance ofand lower than the top of said front carrying-wheel means, and means torock said lever and its Vload upwardly step bystep and to feed saidfront carrying-wheel means forwardly step by step nrelatively to saidframe to a point where 'its agis is beyond the load, the latter thenbeing within the wheel-base of the truck.

174. .ln atruclfr-jael, the combination of a 'trunk-frame, forwarddrum-equipped carrying-wheelmeans for said frame, rear carryingewheelmeans for said frame, the frame having cam-track means on which saiddrum means is adapted to roll and having an eX- tension-foot in front ofsaid forward carrying-wheel means in the lowermost position of the loadand adapted to bear on the lioor and to be raised therefrom, anarticulated l-oad lifting and lowering lever fulcrumed on said frame, astop on said lever eoacting with said Yframe, a spring tending to rocksaid lever, a roller adapted to' travel with said forward carrying-wheelmeans beneath said lever to effect its load lifting and loweringoperation, a sliding ratchet-bar to shift said forward carrying-wheelsand roller and projecting rearwardly sufficiently to enable the operatorby pressing thereon to quickly initially raise said lever before itassumes the load, an operating-handle fulcrumed on said frame near itsrear end, and means including pawls and a pawl-controller whereby saidhandle may feed said ratchetbar step by step forwardly or rearwardly tocorrespondingly raise or'lower the lever and its load, said eam-trackmeansbeing so shaped that when said lever is in its lowered position andin an elevated position said forward carrying-wheels will bear on thefloor and the extension-foot will be raised therefrom and in itsintermediate posit-ions said carrying-wheels will be raised from thefloor and said extension foot will bear on the ioor.

15. In a truck-jack, the. combination of a truck-frame, rearjcarrying-wheel means for said frame, front carrying-wheel means for saidframe, a load lifting and lowering element movably mounted on saidframe, meansy to shift said front carrying-wheel means' forwardly andrearwardly relatively to said frame to elongate and slierten thewheelbase of the truck and relatively to said element to raise and lowerit, and a handle to aetuate said shifting means, the travel of saidcarrying-wheel means being adequate to permit said element while inlowered positionto assume its'load ahead of the axis of said frontcarryingwheel means and to support the load in raised position to therear of said axis.

16; lnv a tiuck-iacl`i, they combination of a truck-frame, rearcarrying-wheel means for said frame, front earryingvvheel means for saidframe, al load lifting and lowering ele* ment movably mounted on saidframe, means to shift said front carrying-wheel refranes means forwardlyand rearwardly relatively to said frame to elongate and shorten theywheel-base of the truck and relatively to said' element to raise andlower it, the travel of said carrying-wheel means being adequate topermit said element while in lowered position to assume `its load aheadof theaxis of said front carrying-wheel means and to support the load inraised position to the rear of said axis, an extensioniloot on saidframe adapted to bear on the floor substantially beneath the load duringa portion of the elevation of the latter and to be raised therefrom, andan operating handle to actuatesaid shifting means and foot.

17. In a truclejack, the combination of a truck-frame, rearcarrying-wheel means for said frame, front carrying-wheel means for saidframe, a load lifting` and lowering element inovably mounted on saidframe, means to shift said front carrying-wheel means forwardly andrearwardly relatively to said frame to elongate and shorten thewheelbase of the truck and relatively to said element to raise and lowerit, the travel of said carrying-wheel means being adequate to permitsaid element while in lowered position to assume its load ahead of theaxis of said front carrying-wheel means and to support the load inraised position to the rear of said axis, an extension foot on saidframe adapted -to bear on the floor substantially beneath the loadduring a portion of the elevation of the latter and to be raisedtherefrom, an operating handle to actuate said shifting means, and meansoperated by said handle to raise said foot from the floor when saidelement is in its lowermost position and also in an elevated position,the foot resting on the floordnring the remainder of the time.

18. In a truck-jack, the combination of a truck-frame, rearcarrying-wheel means for said frame, front carrying-wheel means for saidframe, a load lifting and lowering element movably mounted o n saidframe, means to shift said front carrying-wheel means forwardly andrearwardly relatively to said frame to elongate and shorten thewheelbase of the truck and relatively to said element to raise and lowerit, the travel of said carrying-wheel means being adequate to permitsaid element while in lowered position to assuine its load ahead oftheaxis of said front carrying wheel means and to support the load inraised position to the rear of said axis, an extension foot on saidframe adapted to bear on the floor substantially beneath the load duringa portion of the elevation of the latter and to be raised therefrom` anoperatw ing handle to aetuate said shifting means, means operated bysaid handle to raise said foot from the fioor when said element is inits lowermost position and also in an elevated positiomthe foot restingon the licor dnring the remainder of the time, and means operated bysaid handle to raise said front carrying-wheel means from the floorduring a part of the load-lifting operation.

19. In a truck-jack, the combination ot a truck-frame, rearCarrying-wheel means for said frame, front earryingnvheel means ttorsaid frame, a load lifting and lowering ele ment movahly mounted on saidtraine, means to shiftsaid front earryingnvheel means forwardly andrearwardly relatively to said frame to elongate. and shorten thewheelbase of the truck and relat-ively to said element to raise andlower it, the travel ot said earryingwheel means being,` adequate topermit said element while in lowered position to assume its load aheadof the axis of and forwardly below the top of said liront carryingwvheelmeans and to support the load in raised position to the rear ot saidaxis, and a handle to aetuate said shifting means.

20. In a truck-jack, the Combination ol a truck-frame, rearcarrying-wheel means for said frame, front carrying-wheel means for saidframe, a load liftingl and lowering` element movably mounted on saidframe, means to shift said front carrying-wheel means forwardly andrearwardly relatively to said frame to elongate and shorten thewheel-hase of the truck and relatively to said element to raise andlower it, the travel of said carrying-wheel means being adequate topermit said element while in lowered position to assume its load aheadot the axis of and `forwardly below the top of said front earrying-wheelmeans and to support the load in raised position to the rear of saidaxis, an extension Atoot on said trame adapted to hear on the floorsubstantially beneath the load during a portion of the elevation of thelatter and to he raised therefrom, an operating handle to aetuate saidshitting means, means operated hy said handle to raise said foot fromthe floor when said element is in its lowermost position and also in anelevated position, the foot restingon the floor during Jthe remainder ofthe time, and means operated by said handle to raise said frontearryingwvheel means lfrom the tloor during a part of the load-liting;operation.

l Ii witness whereoll I have hereunto set my ian HARRY C. BUFFINGTON.

